Answer:
Option (B)
Explanation:
By using the property of a triangle → " Sum of interior angles of a triangle is 180°"
Therefore, (4x - 40) + (x + 20) + x = 180°
(4x + x) + (-40 + 20) = 180°
5x - 20 = 180
5x = 180 + 20
5x = 200
x = 40
Therefore, value of x will be 40.
Option (B) will be the correct option.